Here's a small snippet from the Times:
The problem is as universal as cockroaches, and seemingly as unsolvable. Urban dog ownership demands a balance of love and duty, and not everyone is dutiful about cleaning up after the morning walk. Cities have tried everything from the postal service (a Spanish mayor mailed the stuff back to dog owners) to shaming (some cities have publicized the names of offending owners) to bribery (some parks in Mexico City offered free Wi-Fi in exchange for bags of waste).
Naples has opted for science and technology. The idea is that every dog in the city will be given a blood test for DNA profiling in order to create a database of dogs and owners. When an offending pile is discovered, it will be scraped up and subjected to DNA testing. If a match is made in the database, the owner will face a fine of up to 500 euros, or about $685.
Read the rest on nytimes.com.